Valve Adjustment - Stephen Karlan (Dali Meeow)

 You must start with a cold engine. Put newspaper or drain pan under the cylinder heads to catch the oil drips. Remove alternator cover using 4mm Allen wrench. Check alternator belt for cracks and tension and then leave cover off for valve adjustment.

 Remove round black rubber timing hole plug (size of quarter) located on right side of engine (above and to the rear of the cylinder head) by grabbing the edge of the plug with a hemostat (medical tweezers, marijuana roach holder) and pulling or carefully pry it out with a long screwdriver. Timing marks will be seen inside of this hole later on during the adjustment procedure.

 Remove black plastic strip ("4 Valve" imprinted on part) covering the spark plug by hand. Remove plug wire from plug by using 2-inch long black plastic loop tool contained in your BMW tool kit. The purpose of the black plastic loop tool is to give you a handle to pull on that will pull the plug wire off the plug. Holding onto the loop end, point open side toward rear of bike while hooking the tool onto the plug wire boot, then pull out to remove the plug wire. Use compressed air to blow out plug hole before removing plug -- there will be dirt in that hole that you don't want in your cylinder !! At the very least, use a tube or straw to direct the air and lots of lung force. Remove spark plug using tool kit wrench. Place a pan/newspaper under the valve cover to catch the small amount of oil that will drip out when you loosen the four valve cover Allen screws. Loosen the Allen screws with a 6mm wrench and remove the valve cover; lightly tap if it's stuck.

 With bike on centerstand and in neutral, use appropriate socket (5/8-in. or 17mm, depending on bike) to turn the lower alternator drive pulley (and engine) clockwise. Insert long screwdriver into either spark plug hole while turning engine over; when screwdriver is being pushed out, start looking for timing marks. Use a small flashlight to illuminate the flywheel marks. The marks, in order, are "Z", "S" and "OT". Center "OT" in the timing hole opening.

 Optional method #1 for moving the cylinders into place: Instead of looking at the flywheel index marks, remove both spark plugs and put the bike on the center stand in 5th gear. Put a long screwdriver into either spark plug hole and push it against the piston crown. Rotate the rear wheel until the screwdriver projects the maximum distance out of the cylinder. Rock the engine by moving the rear wheel slightly back and forth to get the piston at the very top, OT.

With OT centered, the valves on one side of the engine will "wiggle" a little bit. If they do not "wiggle", check the valves on the opposite side of the engine. One side or the other must wiggle. Adjust valves using 10 mm box wrench, 3mm Allen and two feeler gauges.

BMW recommends the following two feeler gauge dance step. One gauge is used to adjust the intake (or exhaust) valve while the second feeler gauge is positioned under the adjoining intake (or exhaust) valve to stabilize and prevent the rocker from canting.

 After the first valve is adjusted, the second valve will then be adjusted while the first is stabilized. To check if a valve is properly adjusted, attempt to insert the next thicker size of feeler gauge -- it should be too big to fit. The valve clearance may change as you tighten the lock nut. Experiment with tightening technique to maintain clearance as you tighten, and recheck the clearances after all four valves on one side have been adjusted.

 The two exhaust valves are located nearest to the exhaust pipe. Adjust exhaust = .012 in (.30 mm). Adjust intake = .006 in (.15mm). Rotate engine 360 degrees, center OT in timing hole, and adjust the valves on the other side.

 ROCKER ARM SIDEPLAY ADJUSTMENT

Mick McKinnon points out that there is one additional gap to check while the valve covers are off. The rocker arms, which are the vertical metal pieces that contain the valve adjustment nuts, will move up or down when pushed by hand. Measure the two gaps where the rocker arms contact the horizontal piece at the bottom. This horizontal piece has several names, including lower rocker arm bearing carrier (LRABC) and rocker arm end plate. This lower rocker arm bearing carrier (LRABC) is held in place by three T45 torx screws in a triangle pattern (on its side) and one large head bolt. The gaps should be between .05mm and .30mm. The smaller the gap the quieter the engine. The procedure is to loosen the 3 Torx screws and, after marking the lower head bolt, loosen it also. Snug them back up just enough to hold an adjustment and then tap the LRABC until you have about .05mm end play (gap). Check the gap after tightening because it may tighten up slightly as you torque the screws and bolts back to spec. Retorque the T45 torx screws to 15 ft.lb. Retorque the head bolt to 17 ft.lbs. and then turn the bolt an additional 180-degrees (torque it and then move the wrench through another half circle).

 Clean valve covers and reinstall; the gasket surface MUST be free of all oil film or they won't seal. Be certain the center donut gasket is in place on the valve cover !!! Reinstall sparkplug, plug wire and valve cover strip; alternator cover - reinstall top right Allen bolt first; timing hole plug - be careful when reinstalling this plug that you do not push it all the way through, into the hole. Editors Note: One trick is to stab the rubber plug in the middle with a sharp awl to hold it in place while you carefully push the edges in with a long screwdriver. 

Copyright© 1997, Stephen Karlan(Dali Meeow) <dali@netrox.net>, Miami, Florida